In general:1/Introduction: your hypothesis and what make you think it so.2/Describe your experimental setup so that it can be replicated by someone else just from the note3/Record and describe the results of the experiment, and present any statistical analysis of the results4/(In short report it can be mixed with 3) concludes if your hypothesis was confirmed or not and why it is (or could) be so.

Patrick

Science has proof without any certainty. Creationists have certainty without
any proof. (Ashley Montague)

My style:1. Objective: the main point of your experiment (e.g: decide in which temperature sugar dissolve best in water)2. Background: describe why you did the experiment2. Hypothesis: write what the theory say about your experiment. You may do it just briefly.3. Experiment: list all your materials and tools, and also describe your method. Try some flow chart to write your methode4. Result: contain your result. You may add some necessary calculation5. Discussion: discuss about your result. Write why your experiment give you such result, and where will it lead you6. Conclusion: make sure it answer your objective

A good lab report has a format that includes five main sections. They are the introduction, methods and materials, results, discussion and conclusion, and citation. You can find many examples of how to write a biology lab report on web. Remember that lab reports are individual assignments. You may have a lab partner, but the work that you do and report on should be your own. When you are writing about methods and results, be sure to use past tense because you have completed the experiments by the time you begin writing.